Our 99 Contour with the 2.5L duratec engine went to the shop with an axle problem. We got back and the check engine light was on. The clamps were gone from the air filter and the the Tube Assembly hose, F6RZ-6758-A, was broken off where it goes to the valve cover. The hose runs from near the air filter to the valve cover. I think it is used to reburn fumes, but don't know for sure. I found some replacement clamps for the air filter. Car seems to idle and drive fine.

1. Could this tube have been the cause of the check engine light and P0171 code? Will replacing the hose fix it?
2. What is the tube for? What does it do?
3. Would the "open" air filter housing have been part of the problem?

 

Hi and welcome !
I would say you covered it all pretty well.

 

hanky said it.
P0171 means lean condition on bank 1. A lean condition occurs if there is too little fuel or too much air. In your case it was too much air.